TOPIC: TEETH ANOMALIES
🌟IMPORTANT POINTS TO REMEMBER
🔸MACRODONTIA AND MICRODONTIA: Teeth are larger than normal in macrodontia.
🔸AMELOGENESIS IMPERFECTA: It has various types – hypoplastic type (enamel of the affected teeth fails to develop to its normal thickness), hypomaturation type (enamel shows a mottled appearance; it is softer than normal and appears cloudy white, yellow or brown), hypocalcification type (penetrated by a sharp instrument with pressure) and hypomaturation/hypocalcification (enamel is usually mottled and discoloured). Radiologically hypoplastic variety shows square-shaped crown, thin enamel and low or absence of cusps, and hypomaturation shows density of the enamel is same as that of dentine and thickness of the enamel is normal.
🔸DENTINOGENESIS IMPERFECTA: It is also called hereditary opalescent dentine and Capdepont teeth. Type I dentinogenesis imperfecta shows osteogenesis imperfecta with opalescent teeth, while type II dentinogenesis imperfecta reveals isolated opalescent teeth. Teeth affected by dentinogenesis imperfecta show a high degree of amber-coloured translucency and a variety of colours from yellow to blue-grey. Radiologically teeth have bulbous crowns and cervical constriction and may also reveal attrition of the occlusal surfaces.
🔸DENTINE DYSPLASIA: Teeth affected by type I (radicular/rootless teeth) dentin dysplasia have normal colour and shape in both the dentitions, and extreme tooth mobility. Radiologically type I shows pulp is almost completely obliterated and roots are markedly short or absent and type II shows thistle tube–shaped or flame-shaped canals.
🔸REGIONAL ODONTODYSPLASIA: It is also called ghost teeth and odontogenesis imperfecta. Erupted teeth demonstrate smaller irregular crowns that are yellow to brown, often with a very rough surface. Radiographically altered tooth demonstrates extremely thin enamel and dentine surrounding an enlarged radiolucent pulp, resulting in a pale wispy image of the tooth – ghost-like appearance.
🔸GEMINATION: It is also called twinning. Gemination occurs when tooth bud of single tooth attempts to divide. It often presents with an enlarged notched crown, two pulp chambers and single root and pulp canal.
🔸FUSION: It is also called synodontism. Fusion usually causes a reduced number of teeth in the arch. Radiographically, anomalous tooth looks like two teeth stuck together and often the dentine is confluent.
🔹CONCRESCENCE: Concrescence is a union of two adjacent teeth by cementum alone without the confluence of the underlying dentine.
🔸DILACERATION: Dilaceration is an abnormal angulation or bend in the root or less frequently in the crown of a tooth. The appearance like a ‘bull’s eye’ is appreciated when the apical end of the dilacerated root is directed buccally or lingually.
🔸TALON CUSP: It is also called interstitial cusp, tuberculated premolar, odontoma of axial core type and occlusal enamel pearl. It shows radiolucent lines extending in the cusp shadow, suggestive of pulp horns.
🔸DENS IN DENTE: It is also called dilated odontome, dens invaginatus and gestant odontome. Dens in dente is commonly found in maxillary lateral incisor. It reveals a deep fissure or pit on the surface of the tooth. Radiographically there is greater radiodensity present where infolding occurs.
🔸DENS EVAGINATUS: It is also called Leong’s premolar. It is a cusp-like elevation of enamel located in the central groove or over the lingual ridge of the buccal cusp of the permanent premolar or molar teeth. Covering of opaque enamel shows underlying dentine core.
🔸TAURODONTISM: It is an enlargement of the body and the pulp chamber of a multirooted tooth with apical displacement of the pulpal floor and bifurcation of the roots. The hallmark of taurodontism is an extension of the rectangular pulp chamber into the elongated body of the tooth.
🔸ENAMEL PEARL: It is also called enameloma. Ectopic enamel refers to the presence of enamel at unusual locations, mainly the tooth root. Enameloma is identified as a smooth, round radio-opaque structure.
🔸ANODONTIA: It refers to a total lack of tooth development. Oligodontia indicates the lack of development of six or more teeth. Hypodontia denotes the lack of development of one or more teeth.
🔸SUPERNUMERARY TEETH: The most common site is maxillary incisor region (mesiodens), followed by maxillary or mandibular fourth molars (distodens). Those occurring in the molar area are parateeth or paramolars.
🔸NATAL & NEONATAL TEETH: The teeth that erupt in the oral cavity at the time of birth are called as ‘natal teeth’ and teeth that erupt prematurely in the first 30 days of life are called as ‘neonatal teeth’.
🔸TRAMLINE: On the radiograph canal is seen as two radio-opaque parallel white lines passing above the inferior border of the mandible. This line is called the tramline.
🔸WINTER LINES: These are the imaginary colour-coded lines, which are useful to assist in disimpaction of an impacted tooth. The first line is called the white line (along the occlusal surface of erupted molars), amber line (along crest of interdental bone between first and second molars) and red line (perpendicular drawn from while line point of application of elevator).
🔸TRANSPOSITION: It literally means change in the order. In the context of teeth, it is defined as the change in the position of teeth.
🔸INTERNAL RESORPTION: The tooth appears pink. Pink tooth appearance results from hyperplastic pulp tissue filling the defect. Resorption of the root is seen. The root becomes blunt in appearance in place of a normal conical shape. There is a widening of the pulp canal and pulp chamber.
🔸HYPERCEMENTOSIS: It is also known as cementum hyperplasia and exostosis of the root. There is blunting and rounding of the apex of the root.
📌MULTIPLE CHOICE QUESTIONS (MCQs) :
💡When teeth are of normal size and the jaw is smaller than normal, the condition is known as
- Microdontia
- Relative macrodontia
- Macrodontia
- Regional odontoplasia
Answer: 2
💡Ghost teeth is another name of
- Odontogenesis imperfecta
- Dentinogenesis imperfecta
- Regional odontoplasia
- a and c
Answer: 4
💡When tooth bud of a single tooth attempts to divide, it leads to
- Concrescence
- Gemination
- Dilacerations
- Regional odontoplasia
Answer: 2
💡When there is the union of two adjacent teeth by cementum alone without the confluence of the underlying dentin, it is known as
- Dilacerations
- Regional odontoplasia
- Concrescence
- Gemination
Answer : 3
💡Tuberculated premolar or occlusal enamel pearl is a synonym of
- Talon cusp
- Dens evaginatus
- Hyperdontia
- Gemination
Answer: 1
💡Dilated odontome or gestant odontome is a synonym of
- Dens evaginatus
- Dens in dente
- Enamel pearl
- Talon cusp
Answer : 2
💡Another name for enamel pearl is
- Dens evaginatus
- Enameloma
- Dentinoma
- Talon cusp
Answer : 2
💡Leong’s premolar is a synonym of
- Talon cusp
- Dens evaginatus
- Hyperdontia
- Gemination
Answer: 2
💡Cementum hyperplasia or exostosis of root is a synonym of
- Twinning
- Gemination
- Hypercementosis
- Cementoblastoma
Answer : 3
💡Extension of rectangular pulp into the elongated body of the tooth is a hallmark of
- Hyperdontia
- Oligodontia
- Taurodontism
- None of the above
Answer : 3
💡Multiple supernumerary teeth have been associated with the condition
- Cleidocranial dysplasia
- Gardner syndrome
- Marfan syndrome
- a and b
Answer: 4